Today's PC fonts are optimized for use by knowledge workers. They do an excellent job at using content weightings such as bold, underlining, or italics, and supporting other information structures. For children and other users struggling to read and write on a computer device, fonts for productivity do nothing to aid their struggle. For example, productivity fonts do not engage the children and help them understand the letters, words, and numbers they represent. Furthermore, in order for word interactivity to be added to programs, a developer must typically write software code to handle the specific interactive circumstances. Font designers and educators do not have the ability to provide interactivity to the fonts in a customizable fashion.